For the cooling of internal combustion engines used, for instance, in motor vehicles, it is a matter of prior art to position a heat exchanger in the engine compartment of the motor vehicle. In this first cooling circuit, a cooling agent flows through the internal combustion engine, is heated up, and then cooled down again during its subsequent flow through the heat exchanger.
It is also a matter of prior art to position a second cooling circuit with a second heat exchanger in the engine compartment of the motor vehicle, for instance for the purpose of cooling a charge air cooler or an exhaust gas cooler.
Such heat exchangers generally consist of an inlet tank positioned on the input side, which are flooded with the cooling agent intended for cooling, and of an outlet tank positioned on the output side, from which the cooled cooling agent flows out after having flooded the heat exchanger. Typically, multiple pipes are arranged parallel to each other between the inlet tank and the outlet tank, which can be flooded by the cooling agent intended for cooling. Between these pipes, which may also be embodied as flat pipes, so-called fins are arranged, which can be flooded with air, in order to improve the heat dissipation. These fins can take a meandering form or a similar form, and may be brazed onto on or two adjacent pipes in the area of its curve. This creates a mechanically solid and heat-conducting connection between the fins and the pipes of the heat exchanger.
An arrangement of two heat exchangers with different performance requirements or heat transfer capacities is laborious since two separate systems must be integrated into the engine compartment, and furthermore, it significantly reduces the available construction volume in the engine compartment of a motor vehicle.
In order to reduce the construction volume needed for these two heat exchangers as well as production costs, it is also a matter of prior art to embody both heat exchangers in an integrated manner in a single physical unit. Such arrangements are also referred to as multiple-circuit multiple-row heat exchangers, since they feature multiple cooling circuits, and since these are arranged in at least two rows.
Typically, both heat exchangers are positioned with their rows of pipes serially in the air flow direction, so that an air flow serially flows through both rows of pipes of the heat exchanger.
From US Patent Application Publication No. 2014/0360705 A1, a heat exchanger is known featuring a first cooling circuit for the cooling of a first cooling fluid for the cooling of an internal combustion engine, and a second cooling circuit for the cooling of a second cooling fluent for the cooling of a charge air cooler. The cooling processes are performed in two separate spaced cooling systems each of which featuring multiple pipes flooded with a respective cooling agent, and fins arranged between these pipes. The cooling systems are arranged serially in the driving direction of a motor vehicle containing one of these cooling systems, such that the fins of both cooling systems are flooded sequentially by air.
It is disclosed that the fins extend either between the respective pipes of a cooling system, or between the pipes of the two cooling systems.
By combining two cooling systems within a so-called multiple-row heat exchanger, a better utilization of the space within the engine compartment of a motor vehicle is achieved. Furthermore, the parallel arrangement of the pipes and the fins improves the throughflow of the two cooling systems, reduces the aerodynamic drag of the outside air, and therefore improves the total heat dissipation function of the cooling systems.
The task of US Patent Application Publication No. 2010/0044013 A1 is to provide a heat exchanger for multiple cooling circuits which are easier, cheaper, and more simple to manufacture. For these purposes, two separate so-called core areas of a heat exchanger assembly are provided, each of which featuring a plurality of pipes and fins (cooling fins). The core areas are positioned in parallel and spaced from each other in the engine compartment of an internal combustion engine such that the fins can be flooded with air.
Depending on the construction and the manufacturing process, the heat exchangers are fitted with uniform fins in terms of their form, their extent, and their mutual spacing.
When a heat exchanger is flooded with a fluid such as air, this air flow experiences an aerodynamic drag. This brings about a difference between a fluid pressure ahead of and after the heat exchanger. This difference is also referred to a pressure drop or as a loss of air pressure.
In such multi-circuit and multi-row heat exchangers according to prior art, there is a disadvantage in that the possibilities of modifying, the heat exchangers that are operated independently from each other, to specific performance specifications while maintaining a specified maximum permitted loss of air pressure are limited.
The task of the invention is to provide a heat exchanger which allows for a flexible modification of the various performance specifications for different cooling circuits of the heat exchanger, and which is easy and cheap to manufacture.